My pc was running really fine, untill suddenly it started freezing, I restarted my pc and the this happens: after the windows logo, my monitor suddenly turns off and then comes back up once the welcome screen show up, and after a few minutes, it suddenly reboots itself without any warning and then the computer freezes right on the options screen during startup (as in bios and other options) and this keeps repeating constantly, I can use windows safe mode, but the normal mode either freezes completely or the monitor acts up and then the pc reboots itself. What does this mean? What do I do?